Microsoft's president of tools and servers plans to resign later this year, as Ballmer says new blood is needed

Longtime Microsoft executive Bob Muglia, president of the company's server and tools business, will step down from his position later this year, according to a Steve Ballmer memo issued Monday to company employees.

Muglia will continue to run the STB (Server and Tools Business) while his replacement is found, Ballmer wrote. He will step down "this summer," according to Ballmer, which means his departure should happen sometime between June and August.

In the memo, Ballmer touted Muglia's considerable accomplishment of building the STB into a $15 billion-a-year business, though he alluded that someone elsemay have been needed to handle the division going forward.

"Bob Muglia and I have been talking about the overall business and what is needed to accelerate our growth. In this context, I have decided that now is the time to put new leadership in place for STB," Ballmer wrote. "This is simply recognition that all businesses go through cycles and need new and different talent to manage through those cycles."

Muglia has been with Microsoft for 23 years, leading development efforts in Microsoft Office, Windows NT and online services businesses. As president of STB, he oversaw Microsoft's development and infrastructure products, including Microsoft Windows Server, SQLServer, Visual Studio, and System Center products, among others.

More recently, Muglia shepherded Microsoft's entry into cloud computing, guiding the rollout of the company's Azure platform. In November, the company rolled out a series of Azure enhancements to entice greater enterprise use.